1. Technical Field
The present invention relates to an image stabilization mechanism for a camera module.
2. Description of the Related Art
Recently, a variety of camera modules including a video camera, a still camera, and a camera unit installed in a portable electronic apparatus such as a mobile phone are equipped with an image stabilization mechanism to compensate for image blurring caused by a camera body shake.
The image stabilization mechanism includes a lens driving mechanism, an imaging device driving mechanism, and an electronic compensation mechanism. When an image leans in the direction perpendicular to the optical axis due to the tilting of the optical axis resulting from camera shake, the lens driving mechanism temporarily moves some lenses (or lens group) constituting a lens system in a direction perpendicular to the optical axis to change the optical path of the lenses (compensation lens), thus forming the image of a subject at a predetermined position on an image formation surface. The imaging device driving mechanism moves an imaging device so that an image formation position deviating because of camera shake becomes a predetermined image formation position. The electronic compensation mechanism compensates for the deviation of an image formation position due to camera shake with electronic manipulation.
The lens driving mechanism or the imaging device driving mechanism needs to move the compensation lens or the imaging device in the two directions (X-axis direction and Y-axis direction) which are perpendicular to the optical axis. To this end, an image stabilization mechanism of patent document 1 has been proposed.
The image stabilization mechanism 50 according to the patent document 1 includes a base plate 52, an X-axis direction slide 54X for sliding the image of the base plate 52 in the X-axis direction, a Y-axis direction slide 54Y for sliding the image of the X-axis direction slide 54X in the Y-axis direction, an X-axis direction actuator 56X for driving the X-axis direction slide 54X, and a Y-axis direction actuator 56Y for driving the Y-axis direction slide 54Y.
However, the image stabilization mechanism disclosed in patent document 1 is problematic in that it includes the X-axis direction slide 54X and the Y-axis direction slide 54Y, so that the number of required parts is large and thereby the structure is complicated. Further, the X-axis direction slide 54X and the Y-axis direction slide 54Y are not independent of each other, and the Y-axis direction slide 54Y is arranged above the X-axis direction slide 54X such that the X-axis direction slide 54X and the Y-axis direction slide 54Y are dependently driven, so that the height of the image stabilization mechanism in the Z-axis direction is undesirably increased. These problems increase cost, make it difficult to miniaturize the image stabilization mechanism, and reduce in positioning accuracy.    [Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-010730